Rivetless concrete wall form panel with plywood facing and metal studding



2 Sheets-Sheet 1 G. F. BOWDEN ETAL RIVETLESS CONCRETE WALL FORM PANELWITH PLYWOOD FACING AND METAL STUDDING w 9 a I a: c 3 m .L d D. m i an FFIG. 9

llmlmlllmil INVENTORS: GEORGE F. BOWDEN RICHA T. DAGIEL By "M 4% a Sept.3, 1968 G. F. BOWDEN ET AL 3,399,859

RIVETLESS CONCRETE WALL FORM PANEL WITH PLYWOOD FACING AND METALSTUDDING Filed Dec. 23, 1966 2 Sheets-Sheet 2 FIG.7 522 INVENTORS:GEORGE F. BOWDEN RICHARD T. DAGIEL United States Patent RIVETLESSCONCRETE WALL FORM PANEL WITH PLYWOOD FACING AND METAL STUDDING GeorgeF. Bowden, Northbrook, and Richard T. Dagiel,

Elk Grove Village, Ill., assignors to Symons Mfg. Company, Des Plaines,Ill., a corporation of Delaware Filed Dec. 23, 1966, Ser. No. 604,420 9Claims. (Cl. 249189) ABSTRACT OF THE DISCLOSURE A rivetless concretewall form panel comprising an upstanding plywood facing that issurrounded by studding in the form of a rectangular metal frameincluding a pair of oppositely disposed vertical frame members and apair of oppositely disposed horizontal frame members, such panel beingcharacterized by the fact that one of the horizontal frame members isremovable and the further fact that the facing is removably held in theframe by way of anchoring strips which are disposed within matingcomplemental grooves in the four frame members and the adjacent edges ofthe plywood facing.

The present invention relates generally to concrete wall form panels andhas particular reference to a prefabricated rectangualr concrete wallform panel which consists of a plywood facing and a reinforcing frame inthe form of metal studding and is adapted to be arranged in anupstanding position and also in edge-to-edge relation with similarprefabricated panels in order to form with such similar panels one sideof a wall form into which wet concrete may be poured for wall-formingpurposes.

There has long been on the market a class of reusable prefabricatedconcrete wall form panels which are manufactured by Symons Mfg. Companyof Des Plaines, Ill., and are known commercially as Steel-Ply or Mag-Ply panels, "depending upon whether the metallic studding is formed ofsteel or a magnesium alloy. Such panels are prefabricated in that theyare assembled at the factory rather than in the field, and as previouslyset forth, consist of plywood facings and marginal reinforcing frames inthe form of steel or magnesium alloy studding. The vertical andhorizontal members of the frames are in the form of channel stocklengths which are rolled or extruded to special shape and thenperforated, notched and otherwise fashioned in order that they mayproperly receive and facilitate the use of suitable fastening deviceswhereby adjacent panels may be clamped together in rigid edge-to-edgerelationship and, in addition, opposed panels on the opposite sides ofthe concrete wall form may be fixedly maintained in laterally spacedrelationship. The reinforcing frames of the aforementioned concrete wallform panels also include crossbars which are formed of angle bar stockand extend between the opposed vertical frame members so as to reinforcethe medial regions of the plywood facings of the panels. It is to thisgeneral type of Steel-Ply or Mag-Ply panel that the present inventionspecifically relates.

Heretofore, in the manufacture of a Steel-Ply or Mag-Ply panel, it hasinvariably been the practice to secure the plywood facing to thevertical and horizontal members of the reinforcing frame and also thecrossbars of the marginal reinforcing frame by the use of rivets, theheads of which are tapered and seat within correspondingly taperedcountersinks in the front face of the plywood facing. These rivetsconstitute the sole fastening means for the plywood facing and serve tomaintain the edge portions of the facing in seated relation within therectilinear grooves which are provided for them in the front marginalportions of the vertical and horizontal members of the reinforcingframe.

Where a new panel is concerned, the rivets are in all instances tightand the exposed end surfaces of the tapered heads thereof lie flush withthe front face of the plywood facing so that no evidence of the taperedrivet heads is left in the adjacent side surface of the concrete wallwhen the poured concrete has become set and the panel subsequentlyremoved as well understood in the art. However, after a period of usewherein a concrete wall form panel has been employed in many differentconcrete wall form installations and has been subjected to roughhandling during shipment from one installation to another, the rivetsoften become loose. What is even more important is the fact that when agiven panel has been subjected to moisture as well as extremetemperature differentials, the plywood facing thereof will tend to swelland increase its thickness, while at the same time it will bulgeoutwardly away from the marginal reinforcing frame. In such an instance,the originally flush or coplanar rivet heads will be pulled into theplywood and assume positions well within the lateral confines of thefacing, thus establishing small sockets in the front face of the plywoodfacing. These sockets have their counterparts in the adjacent sidesurface of the finished concrete wall so that small unsightlyprotuberances are left in said adjacent side surface after the panel hasbeen stripped from the wall.

The present invention is designed to overcome the above-notedlimitations that are attendant upon the construcfion and use ofconventional Steel-Ply and Mag- Piy panels, and contemplates theprovision of a novel and improved concrete wall from panel in which thefront face of the plywood facing presents an uninterrupted continuoussmooth wall-forming surface completely across the marginal reinforcingframe from side to side and from top to bottom, the plywood facing beingdevoid of rivets or other fastening devices and the front wallformingface of the facing consequently being devoid of any metal expanses.

The provision of a novel and improved rivetless concrete wall form panelof the character briefly outlined above being among the general objectsof the invention, another and important object is to provide a concretewall form panel in which the plywood facing and studding typereinforcing frame that is associated therewith are readily separablefrom each other for the purpose of panel facing replacement after thefacing of the panel has become worn or damaged beyond furtherusefulness.

In United States Patent No. 3,246,871, granted on Apr. 19, 1966 andentitled Rivetless Concrete Wall Form Panel With Plywood Facing andMetal Studding, there is disclosed a concrete wall form panel which isdevoid of rivets and embodies such a design or construction that theplywood facing is readily removable and, therefore, may be replaced inthe event that it becomes worn or damaged in use. The present concretewall form panel is designed as an improvement over the particular panelwhich is illustrated and described in such patent in that the plywoodfacing of the present panel is much more readily removable from betweenthe two vertical frame members which straddle it, and this is occasionedby the fact that it embodies novel mean-s for releasably anchoring theplywood panel within the studding-type rectangul-ar reinforcing frame.In connection with use of a concrete wall form panel like that of saidPatent No. 3,246,871, it has been found that under certaincircumstances, particularly when the plywood of the facing has becomeswollen due to long exposure to moisture, extreme difficulty isencountered in removing the plywood facing. According to the presentinvention, the plywood facing is held in position between the sidemembers of the studding-type reinforcing frame by expansible andcontractible anchoring strips which may be shrunk or con.-

tracted in transverse size in order quickly and readily to release theplywood facing when it is desired to remove it from the frame forreplacement or repair purposes. Not only do the anchoring strips servetheir anchoring or locking function with respect to the plywood facing,but in certain forms of the invention, they function as sealing gasketsto prevent infiltration of moisture and other foreign matter to theexposed raw side and end edges of the plywood facing.

In the accompanying two sheets of drawings forming a part of thisspecification, several embodiments of the invention are shown.

In these drawings:

FIG. 1 is a fragmentary exploded perspective view of a concrete wallform panel embodying one form or embodiment of the present invention;

FIG. 2 is an enlarged horizontal sectional view taken on the planeindicated by the line 22 of FIG. 1 and in the direction of the arrows;

FIG. 3 is a horizontal sectional view similar to FIG. 2 but ShOWiIlg aslightly modified form of the invention wherein the anchoring strips foranchoring in place the plywood facing are formed of nonresilientmaterial;

FIG. 4 is a horizontal sectional view similar to FIG. 2 but showing theuse of resilient anchoring strips of a different cross-sectional shape;

FIG. 5 is a horizontal sectional view similar to FIG. 4 but showing theanchoring strips as being formed of nonresilient material;

FIG. 6 is a horizontal sectional view similar to FIG. 2 but showing theuse of resilient anchoring strips of a still different shape;

FIG. 7 is a horizontal sectional view similar to FIG. 6 but showing theanchoring strips as being formed of nonresilient material;

FIG. 8 is a fragmentary bottom elevational view of the panel of FIG. 1;and FIG.9 is an enlarged partially exploded vertical section on the line99 of FIG. 1.

Referring now to the drawings in detail and in particular to FIGS. 1 and2, a preferred form of the improved rivetless concrete wall form panelis designated in its entirety by the reference numeral 10 and consistsof a rectangular plywood facing 14 and, in addition, a rectangularmarginal frame 16 which surrounds the facing and constitutes thereinforcing metal studding of the panel. This marginal reinforcing frame16 of the panel 10 includes upper and lower horizontal members 18 and 19and a pair of oppositely disposed vertical frame members 20. The ends ofthe lower horizontal frame member 19 abut against and are welded to thelower ends of the vertical frame members 20 while the upper horizontalframe member is removable from the remainder of the studding in a mannerand for a purpose that will be made clear presently. Intermediatehorizontal crossbars 22 in the form of angle bars extend across the rearface of the plywood facing 14 and have their ends secured by welding tothe opposed or inner faces of the two vertical frame members 20. Suchcrossbars constitute additional parts of the studding-type reinforcingframe 16.

All of the four members of the frame 16 are shallow channel shape incross section and each member includes front and rear outwardlyextending ribs 24 and 26, and 'a connecting web portion 28 between theribs. The web portion of each frame member is provided on its inner faceor side and near the front edge thereof with a longitudinally extending,linearly straight groove of generally semi-cylindrical cross-sectionalconfiguration, the groove that is associated with the upper horizontalframe member 18 being designated by the reference numeral 30, the groovethat is associated with the lower horizontal frame member 19 beingdesignated by the reference numeral 32, and the grooves in the webportions of the vertical frame members 20 being designated by thereference numeral 34. These various grooves are designed for cooperationwith respective elastomeric anchoring strips by means of which theplywood facing 14 is locked in position within said four members of thestudding-type reinforcing frame 16, all in a manner that will bedescribed in detail presently. As best shown in FIG. 1, the web portionsof the four frame members are provided a small distance rearwards of theaforementioned grooves with inwardly extending ribs 36, and these formwith the front marginal portions of said web portions 28 seats for theedge portions of the plywood facing 14.

Except for the means whereby the plywood facing 14 is held in positionwithin the studding-type reinforcing frame, the various horizontal andvertical members of the reinforcing frame 16 remain substantially thesame as the horizontal and vertical frame members of a conventionalSteel-Ply or Mag-Ply concrete wall form panel. The vertical or sidemembers of the frame 16 are equipped for cooperation with conventionalconcrete wall form hardware in the form of (1) T-bolt and wedgeassemblies by means of which adjacent concrete wall form panels inedge-to-edge relationship may be held or clamped together to form oneside of a concrete wall form installation; and (2) horizontal tie roddevices by means of which the opposed and spaced apart sides of theinstallation may be maintained in their spaced apart relationship forreception of poured wet concrete therebetween. Exemplary of aconventional Steel-Ply or Mag-Ply panel having side frame members thusequipped is United States Patent No. 2,640,249, granted on June 2, 1953and entitled Wall Form Panel. Accordingly, each of the vertical framemembers 20 of the reinforcing frame 16 is formed with horizontallyaligned clearance notches 42 in its outwardly extending ribs 24 and 26for passage therethrough of the adjacent ends of horizontal combined tierod and spreader devices (not shown). Horizontal slots 44 are providedin the web portions 28 of the vertical frame members 20 for reception ofthe bolt portions of T-bolt and wedge fastening assemblies (also notshown) which serve to draw adjacent and coplanar concrete Wall formpanels together in edge-to-edge relationship and also to anchor theadjacent ends of the aforementioned combined tie rod and spreaderdevices. For a full disclosure of a concrete wall form panel which issecured in position in a concrete wall form installation by suchconcrete wall form hardware, reference may be had to aforementionedPatent No. 2,640,249, it being borne in mind that the horizontal andvertical frame members of the present panel may similarly be secured inposition in a wall form installation.

As shown in both FIGS. 1 and 2, the upper edge of the plywood panelfacing 14 is formed with a coextensive groove which opposes the groove30 in the upper horizontal frame member 18 and is similar in crosssection to the last mentioned groove. Similarly, the lower edge of thefacing 14 is formed with a coextensive groove 52 which opposes thegroove 32 in the lower horizontal frame member 19 and is similar incross section to the last mentioned groove. The side edges of theplywood facing 14 areformed with similar coextensive grooves 54 whichoppose the grooves 34 in the vertical frame members 20 and are ofsimilar cross section. The grooves 50, 52 and 54 are, as shown in FIGS.1 and 2, semicylindrical in cross section as are the grooves 30, 32 and34 in the four frame members.

Interposed and seated in the grooves 50 and 32 is a horizontal elongatedanchoring and sealing strip which bridges the distance between the twovertical frame members 20. Interposed and seated in the grooves 52 and32 is a similar horizontal anchoring and sealing strip 62. Interposedand seated in the grooves 54 and the opposing grooves 34 are verticalanchoring and sealing strips 64, these latter strips bridging thedistance between the upper and lower horizontal frame members 18 and 19when the panel as a whole is in its finished form or condition. Thevarious anchoring and sealing strips in the form of the invention shownin FIGS. 1 and 2 are preferably formed of a suitable elastomericmaterial such as rub her (natural or synthetic), or a rubber substitutesuch as Hycar, or a plastic material possessing a fairly high stretchmodulus of elasticity so that upon stretching the material, itscross-sectional area will diminish appreciably. These anchoring andsealing strips are disposed within the cylindrical voids that areestablished by the mating pairs of opposed grooves under compression andthey thus function in the manner of anchoring keys to hold the panelfacing in position within the reinforcing frame 16 and against sidewisedisplacement and consequent removal. The mating grooves 30 and 52 formbetween the upper horizontal frame member 18 and the upper edge of thefacing 14 an elongated horizontal void for the strip 60; the matinggrooves 32 and 52 between the lower horizontal frame member 19 and thebottom edge of the plywood facing form an elongated horizontal void forthe strip 62; and the mating grooves 34 and 54 between the verticalframe members 20 and the side edges of the facing form elongatedvertical voids for the strips 64.

When the anchoring and sealing strips are formed of elastomeric materialas in the concrete wall form panel of FIGS. 1 and 2, they are made ofslightly greater thickness or diameter than their respective voids inorder that when they are in their operative or looking position, theyare under compression.

The lower horizontal frame member 19 and the two vertical frame members20 of the studding-type marginal reinforcing frame have their adjacentends welded together as heretofore pointed out. The upper horizontalremovable frame member 18 is releasably held in position between theupper ends of the vertical frame members 20 by means of bolts and nutassemblies 70. The latter pass through holes 72 in the web portion 28 ofthe upper horizontal frame member 18 and through the vertically alignedholes 74 in the horizontal part or flange of a horizontal anglepiece 76which extends across the upper ends of the vertical frame members 20 andis welded at its ends to the inner opposed side faces of the Webportions 28 thereof. As shown in FIG. 8 of the drawings, the lower endsof the grooves 34 in the vertical frame members 20 are exposed and theends of the web portion 28 of the lower horizontal frame member 19 areprovided with semicircular grooves 80 which are disposed opposite tosaid exposed lower ends of the grooves 34, 54 for the anchoring andsealing strips 64 being open to atmosphere and are, consequently,readily accessible for the particular purpose to be mentioned hereafter,As shown in FIG. 1, the upper ends of the grooves 34 in the verticalframe members 20 are exposed and the ends of the web portion 28 of theupper horizontal frame member 18 are provided with semicircular grooves82 which are disposed opposite to said exposed upper ends of the grooves34 and result in the upper ends of the elongated vertical voids beingexposed to atmosphere.

In assembling the concrete wall form panel of FIGS. 1, 2, 7, 8 and 9,the three frame members 20, 19 and 20 and the transverse anglepiece 76are first welded together as shown in FIG. 1. Thereafter, the anchoringand sealing strip 62 is placed in the elongated horizontal groove 32 inthe lower frame member 19 and arranged so that it bridges the distancebetween the lower ends of the two vertical frame members 20 and the endsthereof terminate adjacent to the lower ends of the aforementionedvertical voids that are formed by the mating grooves 34 and 54 betweensaid vertical frame members 20 and the side edges of the plywood facing14. After this step or operation, the two strips 64 are cut fromelastomeric anchoring and sealing stock so that they are appreciablylonger than the aforementioned vertical voids. After proper cutting ofthe vertical anchoring and sealing strips 64, such strips are placed inthe grooves 34 in the opposed inner faces of the web portions 28 of thevertical frame members 20. After so positioning such strips 64, theupper ends of the strips are passed through the exposed upper ends ofthe aforementioned vertical voids to the end that they project above theupper ends of the vertical frame members 20, and the lower ends of saidstrips 64 are passed through the exposed lower ends of said verticalvoids to the end that they project beyond the lower ends of the verticalframe members 20. After positioning of the anchoring and sealing strips64 in the aforementioned manner, such strips are then stretched to suchan extent that the resulting reduction in their respective diameters orcross-sectional areas will permit the plywood facing 14 to be readilyslid downwards and endwise in the space between the threewelded-together frame members 20, 19 and 20 as shown by the arrow inFIG. 9. In connection with downward sliding movement of the plywoodfacing 14, the grooves 54 in the side edges of the facing are broughtinto opposed relation with the inner portions of the strips 64. Duringfinal downward sliding movement of the plywood facing, the elongatedhorizontal groove 52 in the bottom edge of the facing is brought intostraddled or seated relation with the upper portion of the anchoring andsealing strip 62 with the result that such strip is maintained in acompressed condition in the aforementioned elongated horizontal voidwhich is formed by the grooves 32 and 52. At this time, the plywoodfacing 14 will assume its proximate final position within the U-shapedportion of the metal studding which is represented by the three framemembers 20, 19 and 20. The stretching or tensioning of the anchoring andsealing strips 64 is thereupon released with the result that thediameters or cross-sectional areas of such strips will be increased insuch manner that the strips will fill and be compressed within the voidsthat are formed or occassioned by the mating grooves 34 and 54.Thereafter, the loose or free ends of the strips 64 are severed to theend that said strips have no end portions which project beyond the endsof the vertical frame members 20 and said strips 64 are confined in acompressed condition wholly Within the aforementioned vertical voidsconsisting of the mating grooves 34 and 54. After severing the looseends of the vertical anchoring and sealing strips 64, the plywood facing14 is effectively locked or keyed in the U-shaped portion of thereinforcing frame 16 consisting of the frame members 20, 19 and 20, thestrips 62 and 64 serving to hold the panel against forward displacementWith respect to the frame and the inwardly extending ribs 36 serving tohold the facing against rearward displacement with respect to the frame.With the plywood facing 14 thus secured in position, the elastomericcombined anchoring and sealing strip 60 is then cut to length andpositioned within the elongated horizontal groove in the upper framemember 18. Thereafter, such frame member is caused to overlie theanglepiece 76 in such manner that its ends fit between the upper ends ofthe vertical frame member 20. The nut and bolt assemblies 70 are thenpassed through the holes 72 and 74 and tightened so as to draw the upperhorizontal frame member 18 into place and effect compression of thestrip 60 in the upper horizontal void consisting of the grooves 30 and50. The entire plywood panel 14 is thus placed under compression in alongitudinal direction so that the compressional load is shared by thehorizontal anchoring and sealing strips 60 and 62 which are placed undercompression and in combination with the compressional forces which existin the vertically extending anchoring and sealing strips 64 result inthe panel being securely locked in place Within the completedstudding-type reinforcing frame 16. After completion of the panel byproperly securing in place the upper frame member 18, the aforementionedexposed upper and lower ends of the vertical voids may be plugged orsealed if desired.

In the form of the invention of FIGS. 1, 2, 8 and 9, the strips 60, 62and 64 are formed of elastomeric material as heretofore described and,as a consequence, in addition to their anchoring function whereby theplywood panel facing 14 is locked in position within the studdingtypemetal reinforcing frame, the strips perform a sealing function in thatthey protect the raw edges of the plywood facing against infiltration ofmoisture or other foreign matter. Under certain circumstances, thisadditional sealing function may be dispensed with by utilizing metal,wood, or other incompressible strips in place of elastomeric ones. Sucha panel employing incompressible cylindrical locking strips isfragmentarily disclosed in FIG. 3. Although only one of the lockingstrips, namely, the locking strip 164 that is associated with one of thevertical side frame members, is shown in this view, it is to beunderstood that the other four strips are of similar construction. Dueto the similarity of parts as between the panel of FIGS. 1, 2, 8 and 9and the panel that is shown fragmentarily in FIG. 3, and in order toavoid needless repetition of description, similar characters ofreference but of a higher numerical order have been applied to thecorresponding parts as between the disclosures of FIG. 2 and FIG. 3. Itis obvious that in assembling the panel of FIG. 3, the vertical lockingstrips 164 will be cut to their proper lengths before the facinginstallation is made since there will be no stretching thereof fordiameter reduction purposes. When incompressible anchoring strips areused, the holes 80 and 82 may, of course, be omitted.

In FIGS. 4, 5, 6 and 7, various alternative forms of anchoring orlocking strips are illustrated, utilizing the same basic plywood panelfacing and metal studding arrangement as that of FIGS. 1, 2, 8 and 9.Again, to avoid needless repetition of description, reference numeralsof a progressively higher order have been applied to the correspondingpanel parts as between the disclosure of each of these views and that ofFIG. 2.

In FIG. 4, an elastomeric sealing strip 264 of generally elliptical oroval cross section is shown seated within grooves 234 and 254 in one ofthe side or vertical frame members 220 and the adjacent side of theplywood facing 214, respectively.

In FIG. 5, the anchoring strip 364 is similar in cross sectional shapeto that of the strip 264, but it is formed of an incompressible materialsuch as steel.

In FIG. 6, the strip 464 is formed of an elastomeric material which isrectangular in transverse cross section, and the grooves 434 and 454 inwhich the strip seats are correspondingly of rectilinear design.

In FIG. 7, the strip 564 is formed of an incompressible material, suchas steel, and the cross-sectional shape thereof is similar to that ofthe anchoring strip 464.

The invention is not to be limited to the exact arrangement of partswhich is shown in the accompanying drawings or described in thisspecification as various changes in the details of construction may beresorted to without departing from the spirit or scope of the invention.Therefore, only insofar as the invention is particularly pointed out inthe accompanying claims is the same to be limited.

Having thus described the invention What we claim as new and desire tosecure by Letters Patent is:

1. A rivetless concrete wall form panel comprising an upstandingrectangular plywood facing surrounded by studding in the form of arectangular metal frame including a pair of oppositely disposed verticalframe members and a pair of oppositely disposed horizontal framemembers, the front wall-forming side of said facing and the front rim ofthe frame lying in a common plane, the frame members of each pair beingformed with opposed internal trough-like grooves, the four edges of saidplywood facing being each formed with a trough-like groove which opposesthe groove in the adjacent frame member and, in combination therewith,establishes an elongated void which is coextensive with the thus matinggrooves, and an elongated anchoring strip disposed within each of thevoids and substantially filling the same so as to prevent lateraldisplacement of the plywood panel from the rectangular metal frame whichcomprises the studding, one of said horizontal frame members beingremovable from the frame in order to permit the facing to be slidendwise into and out of the rectangular metal frame, and means forremovably securing said one horizontal frame member in position in theframe, said anchoring strips constituting the sole means for removablysecuring said facing in position within the frame, said plywood facingbeing imperforate and the front wallforming side thereof being devoid ofcountersinks or other socket-like interruptions.

2. A rivetless concrete wall form panel as set forth in claim 1 andwherein the anchoring strips are formed of an elastomeric material andexist under compression between the voids in which they are disposed.

3. A rivetless concrete wall form panel as set forth in claim 1 andwherein the anchoring strips are formed of an incompressible material.

4. A rivetless concrete wall form panel as set forth in claim 1 andwherein the anchoring strips are of cylindrical configuration.

5. A rivetless concrete wall form panel as set forth in claim 1 andwherein the anchoring strips are of elliptical configuration intransverse cross section.

6. A rivetless concrete wall form panel as set forth in claim 5 andwherein the anchoring strips are formed of an elastomeric material andexist under compression in the voids in which they are disposed.

7. A rivetless concrete wall form panel as set forth in claim 1 andwherein the anchoring strips are of rectangular configuration intransverse cross section.

8. A rivetless concrete wall form panel as set forth in claim 7 andwherein the strips are formed of an elastomeric material and exist undercompression in the voids in Which they are disposed.

9. A rivetless concrete wall form panel as set forth in claim 7 andwherein said locking strips are formed of an incompressible material.

References Cited UNITED STATES PATENTS 3,137,909 6/1964 Bonin et al.249191 3,239,986 3/1966 Russell 52-620 X 3,246,871 4/1966 Bowden 2491893,362,674 1/1968 Gilbert 249l92 X I. SPENCER OVERHOLSER, PrimaryExaminer.

J. S. BROWN, Assistant Examiner.

